Single bottle structures with more than one compartment or chamber are well known in the art. Such bottles are commonly used to house ingredients which might be used together or in sequence. For example, one compartment in the bottle could hold shampoo while the other compartment held hair conditioner. In other instances, the ingredients might constitute chemicals to be used together but normally held in a separated state until such actual use. An example would be epoxy glues wherein a resin and catalyst are initially held in separate compartments but then mixed when they are to be used.
Representative examples of twin compartment bottles used over the years are shown, for example, in U.S. Pat. Nos. 2,013,382 issued Sept. 3, 1935 to Garwood; 3,076,573 issued Feb. 5, 1963 to Thomas; and 4,196,808 issued Apr. 8, 1980 to Pardo. The containers in each of these patents constitute hard material such as glass so that in order to express the contents, the bottles must be tilted. The specific inventions in the patents relate mostly to the closure members for the compartments themselves.